Better battery cooling.

Ok, Arizona summer's here and it's reaking havoc on my poor batteries. I've been keeping the car as cool as I can stand to keep it, but while it's sitting there it get hot again. A windshield cover and car cover have helped some, but still haven't prevented the car in to going in to thermal cut back several times already. So I've had a few ideas which might help some. The question is does anyone know the specifics on the battery cooling fan? I looked at it once and noticed it was a panaflo fan, but can't remember if it was a 120 mm size fan or what and also is it the low or high rpm model. If it is the quiet one I'm thinking replacing it with the faster one would help some potentially.

Any thoughts?